Footprints before feet
Tracks in a Polish quarry show four-legged animals walking 18 million years before any body fossil.
- When
- Known to
- ± 3 million years
- Era
- Devonian, Paleozoic
Trackways in 395-million-year-old marine tidal-flat carbonates in the Holy Cross Mountains preserve alternating left-right prints with distinct digits — unambiguously made by a tetrapod. They predate the oldest tetrapod skeletons by roughly eighteen million years, and Tiktaalik, the celebrated fish-tetrapod intermediate, by twenty. The find forced a substantial rewrite of when and where vertebrates first walked.